Mayilee Canizares, Ph.D., from the Krembil Research Institute at the University Health Network in Toronto, and colleagues followed a representative sample of the Canadian population (12,782 individuals) from 1994 to 2011. Participants were interviewed biannually and provided data on sociodemographic factors, behavior-related factors, depression, comorbidities, pain, disability, medication use, and health care use. Participants were grouped based on patterns of the course of back pain during follow-up.

The researchers found that during follow-up, 45.6 percent of patients reported back pain at least once. Of these, four trajectories were identified: persistent, developing, recovery, and occasional (18.0, 28.1, 20.5, and 33.4 percent, respectively). More pain preventing activities, disability, depression, and comorbidities characterized the persistent and developing groups. Across the groups, significant differences were seen in the patterns of medication and health care use, with a general trend of most to least use in the persistent, developing, recovery, and occasional use groups. An increasing trajectory of opioid and antidepressant use was seen in the recovery group.

"The results have important implications for the way we understand back pain as the different trajectory patterns potentially represent subgroups in the population that may require different interventions," the authors write.